xtrabackup备份MySQL报错：InnoDB: Error number 24 means ‘Too many open files‘

1.使用xtrabackup备份MySQL时出现如下报错：

190228 00:30:01 >> log scanned up to (88343615848)xtrabackup: Generating a list of tablespacesInnoDB: Allocated tablespace ID 2 for mysql/plugin, old maximum was 0InnoDB: Operating system error number 24 in a file operation.InnoDB: Error number 24 means ‘Too many open files‘InnoDB: Some operating system error numbers are described at http://dev.mysql.com/doc/refman/5.7/en/operating-system-error-codes.htmlInnoDB: File ./jira/AO_4B00E6_STASH_SETTINGS.ibd: ‘open‘ returned OS error 124. Cannot continue operationInnoDB: Cannot continue operation.

2.查看备份使用的user的ulimit

[root@linux mysql]# ulimit -acore file size (blocks, -c) 0data seg size (kbytes, -d) unlimitedscheduling priority (-e) 0file size (blocks, -f) unlimitedpending signals (-i) 385500max locked memory (kbytes, -l) 64max memory size (kbytes, -m) unlimitedopen files (-n) 1024pipe size (512 bytes, -p) 8POSIX message queues (bytes, -q) 819200real-time priority (-r) 0stack size (kbytes, -s) 8192cpu time (seconds, -t) unlimitedmax user processes (-u) 385500virtual memory (kbytes, -v) unlimitedfile locks (-x) unlimited

3.修改/etc/security/limits.conf

vim /etc/security/limits.conf* soft nofile 65535* hard nofile 65535

重新备份还是报错。

4.修改MySQL的配置文件，增加如下参数：

vim /etc/my.cnfinnodb_open_files=1000

重新备份成功！